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reka · Open weights

Reka Flash 3

Added Oct 15, 2026Open weights

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Use in the app

Reka's 21B reasoning model for chat and coding, served directly by Reka.

  • Reasoning
  • Structured output
Input
Text
Output
Text
Discovery tier
Open weights

Pricing

USD per 1M tokens
Input
$0.11
Output
$0.21

Reference prices as published by the model provider. API example

Specifications

Context window
65.5K
Max output
65.5K
Average output (7 days)
2.7K tokens
Longer than 95% of 465 models

Side by side

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TryMinistral 8BGPT-3.5 TurboLlama 3.2 3b InstructAll 3

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

Intelligence Index

5.6

Better than 2% of 326 scored models

3.8Catalog models by score55.1

Indexes

  • Math Index

    33.7

    Composite of the math evaluations

    Better than 31% of 118 scored models

Document reasoning

  • AA-LCRv1.1

    0.0%

    Reasoning across long documents

    Better than 0% of 309 scored models

Reasoning and knowledge

  • Humanity’s Last Exam

    4.4%

    Expert-level questions across academic fields

    Better than 11% of 323 scored models

  • GPQA Diamond

    52.9%

    Graduate-level science questions

    Better than 11% of 291 scored models

  • MMLU-Pro

    66.9%

    Multi-subject knowledge and reasoning

    Better than 15% of 132 scored models

  • IFBench

    30.4%

    Following precise output instructions

    Better than 5% of 215 scored models

Coding

  • LiveCodeBench

    43.5%

    Recent competitive programming problems

    Better than 37% of 129 scored models

Math

  • AIME 2025

    33.7%

    Competition mathematics, 2025 problems

    Better than 31% of 118 scored models

  • AIME

    51.0%

    Competition mathematics

    Better than 62% of 72 scored models

  • MATH-500

    89.3%

    Competition math problems

    Better than 45% of 73 scored models

Legacy evaluations

  • Terminal-Bench Hard

    0.0%

    Earlier terminal task suite

    Better than 0% of 212 scored models

  • τ²-Bench Telecom

    0.0%

    Tool use in a customer-support simulation

    Better than 0% of 214 scored models

  • AA-LCR (unversioned)

    0.0%

    Long-context reasoning, earlier grading

    Better than 0% of 309 scored models

Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "reka/reka-flash-3",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="reka/reka-flash-3",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

reka

Other reka models, starting with the same family.